Desktop work ........ That covers a LOT of ground, and some of it can really benefit from additional VRAM. PS7 will see further implementation of GPU-specific processing, and LR5 will start GPU implementation. I disagree with your statement.

As a test done using Photoshop CS6 to see the benefits of graphic cards within processing, at least the amount of VRAM doesn't say anything for speed. Typically a GPU with the most VRAM + high processor power did very bad. (AMD Radeon 7970 3Gb).